Mold-releasing agent

ABSTRACT

Disclosed is a mold-releasing agent comprising, as active ingredients, a polyfluoroalkylphosphonic acid represented by the general formula: C n F 2n+1 (CH 2 CF 2 ) a (CF 2 CF 2 ) b (CH 2 CH 2 ) c P(O)(OH) 2  (n: an integer of 1 to 6, a: an integer of 1 to 4, b: an integer of 1 to 3, c: an integer of 1 to 3), or a salt thereof and a polyfluoroalkylphosphonic acid oxyalkylene ester represented by the general formula: C n F 2n+1 (CH 2 CF 2 ) a (CF 2 CF 2 ) b (CH 2 CH 2 ) c P(O)[O(RO) m R′] d (OH) 2−d  (RO: a C 2 -C 6  linear or branched oxyalkylene group, R′: a hydrogen atom, a C 1 -C 20  alkyl group, or aralkyl group, n: an integer of 1 to 6, a: an integer of 1 to 4, b: an integer of 1 to 3, c: an integer of 1 to 3, d: an integer of 1 or 2, m: an integer of 1 to 100). This mold-releasing agent comprises, as an active ingredient, a polyfluoroalkylphosphonic acid oxyalkylene ester having a perfluoroalkyl group containing 6 or less carbon atoms, which is said to have low bioaccumulation potential, but exhibits mold release performance equivalent to that of a mold-releasing agent comprising a compound having a perfluoroalkyl group containing 8 or more carbon atoms as an active ingredient.

RELATED APPLICATION

This application is a 35 U.S.C. §371 national phase filing ofInternational Patent Application No. PCT/JP2010/065384, filed Sep. 8,2010, through which and to which priority is claimed under 35 U.S.C.§119 to Japanese Patent Application No. 2009-210291, filed Sep. 11,2009, the entire disclosures of which are hereby expressly incorporatedby reference.

TECHNICAL FIELD

The present invention relates to a mold-releasing agent. Moreparticularly, the present invention relates to a mold-releasing agenthaving excellent film-forming properties and excellent moldreleasability.

BACKGROUND ART

Currently, silicone oil, wax, talc, mica, tetrafluoroethylene resin, andother mold-releasing agents are used in the molding of polymericmaterials, such as plastic materials and rubber materials, using molds.Although silicone oil, wax, etc., have excellent mold releasability,such mold-releasing agents are transferred to molded products, therebyimpairing uniform coating properties, secondary processability, andother properties; in addition, durability is not sufficient. As fortetrafluoroethylene resin, the durability of mold release effect andsecondary processability are satisfactory; however, it is necessary toperform bake treatment to form a film on the molding surface of a moldin the mold-release process, and the same treatment is required forreprocessing. Consequently, many processes are required.

In order to solve these defects, mold-releasing agents comprising aC₄-C₂₀ polyfluoroalkyl group-containing phosphate ester as one of theiractive ingredients are proposed (see Patent Documents 1 to 3). Thesemold-releasing agents exhibit excellent mold releasability and have alonger mold release life than conventional mold-releasing agents;however, due to the recent trend toward the more complicated shape ofmolded products, there is a demand for mold-releasing agents having muchhigher performance.

Meanwhile, polyfluoroalkyl phosphonates are also widely used as startingmaterials for the synthesis of mold-releasing agents. Compounds having aC₈-C₁₂ perfluoroalkyl group are most likely to develop mold releaseperformance when used as mold-releasing agents. In particular,phosphonate compounds having a perfluorooctyl group and represented bythe general formula:CF₃(CF₂)₇CH₂CH₂P(O)(OC₂H₅)₂are preferably used for this kind of application (see Patent Documents 4to 7).

Incidentally, it is reported that phosphate or phosphonate compoundshaving a C₈-C₁₂ perfluoroalkyl group are biologically degraded in theenvironment and converted to compounds having relatively highbioaccumulation and environmental concentration, causing concerns forexposure during treatment processes, and for release or diffusion fromwaste, treated substrates, etc., into the environment. Moreover,compounds having a perfluoroalkyl group containing 14 or more carbonatoms are very difficult to handle because of their physical andchemical properties, and hence, such compounds are rarely used inpractice.

Furthermore, as for phosphate or phosphonate compounds having aperfluoroalkyl group containing 8 or more carbon atoms, generation andmixing of perfluorooctanoic acids with high bioaccumulation potential isunavoidable during the production of these compounds. For these reasons,companies that produce such phosphate or phosphonate compounds haveretreated from the production of the compounds or promoted the use ofalternative compounds having a perfluoroalkyl group containing 6 or lesscarbon atoms.

However, compounds having a perfluoroalkyl group containing 6 or lesscarbon atoms cause a significant decrease in orientation on the surfaceof a treated substrate, and the melting point, glass transition point(Tg), etc., of the compounds are markedly lower than those of C₈compounds. Accordingly, the compounds are highly influenced by theirenvironmental conditions, such as temperature, humidity, stress, andcontact with organic solvents. Consequently, the desired performancecannot be sufficiently achieved, and durability and other properties areaffected.

PRIOR ART DOCUMENT Patent Document

-   Patent Document 1: JP-B-53-23270-   Patent Document 2: JP-B-53-23271-   Patent Document 3: JP-B-57-48035-   Patent Document 4: JP-B-2-45572-   Patent Document 5: JP-B-3-78244-   Patent Document 6: JP-B-4-4923-   Patent Document 7: JP-B-4-11366-   Patent Document 8: WO 2007/105633 A1

OUTLINE OF THE INVENTION Problem to be Solved by the Invention

An object of the present invention is to provide a mold-releasing agentcomprising, as an active ingredient, a polyfluoroalkylphosphonic acidester having a perfluoroalkyl group containing 6 or less carbon atoms,which is said to have low bioaccumulation potential, and mold releaseperformance equivalent to that of a compound having a perfluoroalkylgroup containing 8 or more carbon atoms.

Means for Solving the Problem

The object of the present invention can be accomplished by amold-releasing agent comprising, as active ingredients, apolyfluoroalkylphosphonic acid represented by the general formula:C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)(OH)₂  [I]wherein n is an integer of 1 to 6, a is an integer of 1 to 4, b is aninteger of 1 to 3, and c is an integer of 1 to 3, or a salt thereof anda polyfluoroalkylphosphonic acid oxyalkylene ester represented by thegeneral formula:C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)[O(RO)_(m)R′]_(d)(OH)_(2−d)  [XI]wherein RO is a linear or branched oxyalkylene group having 2 to 6carbon atoms, R′ is a hydrogen atom, an alkyl group having 1 to 20carbon atoms, or aralkyl group, n is an integer of 1 to 6, a is aninteger of 1 to 4, b is an integer of 1 to 3, c is an integer of 1 to 3,d is an integer of 1 or 2, and m is an integer of 1 to 100.

Effect of the Invention

When released into the environment, the polyfluoroalkylphosphonic acid(salt) and oxyalkylene ester thereof, as an active ingredient of amold-releasing agent of the present invention, undergoes HF-eliminationin the —CH₂CF₂— bonding site of the molecule, and a double bond isformed. The result is then subjected to ozone decomposition etc. to havea structure that is easily decomposed into a compound with lowenvironmental concentration and low bioaccumulation potential. Moreover,the polyfluoroalkylphosphonic acid oxyalkylene ester does not produceenvironmental loading substances (e.g., perfluoroalkyl carboxylic acidshaving 8 or more carbon atoms) in the production process thereof.

A mold-releasing agent comprising the polyfluoroalkylphosphonic acid(salt) and oxyalkylene ester thereof as an active ingredient exhibitseffective mold release performance, even when, for example, it isprepared as an aqueous or organic solvent mold-releasing agent having aconcentration of about 1.0 wt. % or less, and when it is applied to anobject to be subjected to a mold release treatment (e.g., a moldingmold). This excellent effect is attributable to the extremely highsolubility of the polyfluoroalkylphosphonic acid (salt) and oxyalkyleneester thereof in solvents. Using this as an active ingredient, amold-releasing agent having excellent mold releasability can beobtained.

By combining use of the polyfluoroalkylphosphonic acid (salt) andoxyalkylene ester thereof, the mold-releasing agent has a synergisticeffect on improving mold releasability and mold release life. Moreover,since this mold-releasing agent exhibits excellent mold releasabilityand durability, mold contamination caused by the mold-releasing agentcan be reduced, and the dimensional accuracy of the molded product canbe improved.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

The polyfluoroalkylphosphonic acid, which is used as one activeingredient of the mold-releasing agent, is represented by the generalformula:C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)(OH)₂  [I]

The polyfluoroalkylphosphonic acid oxyalkylene ester represented by thegeneral formula:C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)[O(RO)_(m)R′]_(d)(OH)_(2−d)  [XI]which is used as the other active ingredient, is produced by subjectinga polyfluoroalkylphosphonic acid (which is not necessarily the same asthe polyfluoroalkylphosphonic acid [I]) and a polyalkyleneglycol or amonoether thereof represented by the general formula:HO(RO)_(m)R′  [X]to a condensation reaction.

The polyfluoroalkylphosphonic acid of the formula:C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)(OH)₂  [I]is produced by the hydrolysis reaction of a polyfluoroalkylphosphonicacid diester represented by the general formula:C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)(OR)₂  [II]wherein R is an alkyl group having 1 to 4 carbon atoms, n is an integerof 1 to 6, a is an integer of 1 to 4, b is an integer of 1 to 3, and cis an integer of 1 to 3.

The polyfluoroalkylphosphonic acid diester [II], which is used as astarting material for this reaction, is obtained by the reaction of apolyfluoroalkyl iodide [III] of the formula:C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)I  [III]with trialkyl phosphite P(OR)₃. The polyfluoroalkyl iodide [III] is aknown compound and is disclosed in Patent Document 8.

The polyfluoroalkyl iodide [III], which is used as a starting materialfor the synthesis of the polyfluoroalkylphosphonic acid diester [II], isproduced by the addition reaction of a terminally iodized compoundrepresented by the general formula:C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)I  [IV]with ethylene. The ethylene addition reaction is carried out in such amanner that the compound [IV] is subjected to an addition reaction withpressurized ethylene in the presence of a peroxide initiator. The numberof addition is 1 to 3, preferably 1, although depending on the reactionconditions. Although the reaction temperature depends on the degradationtemperature of the initiator used, the reaction is generally conductedat about 80 to 120° C.; when a peroxide initiator that decomposes at alow temperature is used, the reaction can be conducted at 80° C. orbelow.

As a peroxide initiator, tert-butyl peroxide,di(tert-butylcyclohexyl)peroxy dicarbonate, dicetylperoxy dicarbonate,di-n-propylperoxy dicarbonate, diisopropylperoxy dicarbonate,di-sec-butylperoxy dicarbonate, or the like may be used at a ratio ofabout 1 to 5 mol % with respect to the compound [IV], in terms of theprogress and controllability of the reaction.

The terminally iodized compound [IV] is synthesized through a series ofthe following steps:

(1) A perfluoroalkyl iodide represented by the general formula:C_(n)F_(2n+1)I (n: 1 to 6)is reacted with vinylidene fluoride in the presence of a peroxideinitiator as described above in an amount of about 0.1 to 0.5 mol %based on the starting material compound to obtain a compound representedby the general formula:C_(n)F_(2n+1)(CH₂CF₂)_(a)I  [V](2). The compound represented by the general formula [V] is reacted withtetrafluoroethylene in the presence of a peroxide initiator to therebyobtain a terminally iodized compound represented by the general formula[IV] described above. In the general formula [IV], b is an integer of 1to 3, preferably 1 or 2. The organic peroxide initiator as mentionedabove can be used in this reaction in the same amount as in step (1).

Although the reaction temperature of the addition reaction of vinylidenefluoride and tetrafluoroethylene depends on the decompositiontemperature of the initiator used, the use of a peroxide initiator thatdecomposes at a low temperature allows the reaction to occur at 80° C.or less under low-pressure conditions. The reaction is carried out inthe following manner. The perfluoroalkyl iodide C_(n)F₂₊₁I or thecompound [V] is charged in an autoclave, and the internal temperature isincreased to about 10 to 60° C. For example, when the temperaturereaches 50° C., a peroxide initiator dissolved in the perfluoroalkyliodide C_(n)F_(2n+1)I or the compound [V] is added thereto. When theinternal temperature reaches 55° C., for example, vinylidene fluoride ortetrafluoroethylene is added in batches while maintaining the pressureat about 0.1 to 0.6 MPa. After the desired amount of vinylidene fluorideor tetrafluoroethylene is added in batches, aging is carried out, forexample, at a temperature of about 55 to 80° C. for about one hour. Theamount of vinylidene fluoride or tetrafluoroethylene added affects thenumber of vinylidene fluoride skeletons a or tetrafluoroethyleneskeletons b added by the reaction. Generally, a mixture of various avalues and b values is formed.

The fact that these reactions can be carried out at low temperaturesindicates that not only energy usage amount can be reduced, but alsocorrosion due to hydrofluoric acid etc. in facilities can be prevented,thereby reducing the frequency of updating the facilities. Additionally,since more inexpensive materials can be used, capital investment costscan also be kept low, in addition to the decrease in update frequency.

Specific examples of the compound [IV] to which ethylene is addedinclude the following compounds. These compounds are mixtures ofoligomers having various a values and b values. Oligomers that havespecific a value and b value can be isolated by distilling the mixtures.Oligomers that do not have predetermined a and b values can be reusedafter isolation or as the mixtures in the reaction of increasing thenumber of oligomers with vinylidene fluoride or tetrafluoroethylene.C₂F₅(CH₂CF₂)(CF₂CF₂)IC₂F₅(CH₂CF₂)(CF₂CF₂)₂IC₂F₅(CH₂CF₂)₂(CF₂CF₂)IC₂F₅(CH₂CF₂)₂(CF₂CF₂)₂IC₄F₉(CH₂CF₂)(CF₂CF₂)IC₄F₉(CH₂CF₂)₂(CF₂CF₂)IC₄F₉(CH₂CF₂)(CF₂CF₂)₂IC₄F₉(CH₂CF₂)₂(CF₂CF₂)₂IC₂F₅(CH₂CF₂)(CF₂CF₂)₃IC₄F₉(CH₂CF₂)(CF₂CF₂)₃I

The polyfluoroalkyl iodide [III] prepared by the addition reaction ofthe compound [IV] as described above with ethylene can be reacted withtrialkyl phosphite P(OR)₃ having an alkyl group containing 1 to 4 carbonatoms, such as trimethyl phosphite, triethyl phosphite, tripropylphosphite, or tributyl phosphite, to perform the RI-eliminationreaction, thereby obtaining a polyfluoroalkylphosphonic acid diester[II], which is used as a starting material. Without the additionreaction of the compound [IV] with ethylene, the RI-elimination reactionwith trialkyl phosphite does not proceed.

The hydrolysis reaction of the polyfluoroalkylphosphonic acid diester[II] can be readily carried out by stirring at about 90 to 100° C. inthe presence of an acid catalyst, such as inorganic acid typified byconcentrated hydrochloric acid. The resulting reaction mixture isfiltered under reduced pressure, followed by water washing/filtration,acetone washing/filtration, and other methods, thereby obtaining apolyfluoroalkylphosphonic acid [I], which is used as one reactionstarting material, with a good yield of 90% or more.

The obtained polyfluoroalkylphosphonic acid [I] can also be used in theform of a salt after neutralization. The salt is generally formed bytitration with a salt-forming reactant, such as sodium hydroxide,ammonium hydroxide, zinc sulfate, zinc acetate, zinc oxide,triethylamine, morpholine, triethanolamine, ortris(2-hydroxyethyl)amine, while identifying the equivalence point fromthe pH level, to obtain an acidic mono-, di- or tri-valent metal salt,amine salt, or ammonium salt. Examples of polyfluoroalkylphosphonic acidsalts to be obtained include sodium, potassium, lithium, barium,magnesium, calcium, zinc, and other metal salts; ammonium salts;ammonium salts substituted by alkyl groups or cycloalkyl groups, such asmonoethyl, monoisopropyl, diethyl, dicyclohexyl, and triethyl; ammoniumsalts substituted by hydroxyalkyl groups, such as monoethanol,diethanol, triethanol, and diisopropanol; and the like, ofpolyfluoroalkylphosphonic acids.

Examples of the polyalkyleneglycol or monoether thereof represented thegeneral formula:HO(RO)_(m)R′  [X]which is used as the other reaction starting material, includepolyethyleneglycol, polypropyleneglycol, polybutyleneglycol,polyhexyleneglycol, or monoalkyl ether or monoaralkyl ether thereof;preferably, monomethyl ether, monoethyl ether, etc., wherein m is 1 to100, and the number average molecular weight (Mn) is preferably about200 to 4,000, are used.

The condensation reaction between the polyfluoroalkylphosphonic acid [I]and the polyalkyleneglycol or monoether thereof [X] is carried out byheating at a temperature of about 80 to 180° C. using a dehydrationcatalyst, such as concentrated sulfuric acid or concentratedhydrochloric acid. In the reaction, for example, nitrogen bubbling iscontinuously performed to remove produced water from the reactionsystem, thereby promoting the dehydration-condensation reaction.

The reaction mixture comprises about 50 wt. % of unreactedpolyalkyleneglycol (monoether) and about 50 wt. % of reaction product.The reaction product comprises a mixture of a polyfluoroalkylphosphonicacid monooxyalkylene ester [A] represented by the general formula:C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)[O(RO)_(m)R′](OH)and a polyfluoroalkylphosphonic acid bis(oxyalkylene)ester [B]represented by the general formula:C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)[O(RO)_(m)R′]₂

The polyalkyleneglycol (monoether) [X] is used in an equimolar amount ormore based on the polyfluoroalkylphosphonic acid [I]. When the molarratio is about 2, generally about 1.5 to 2.5, the monooxyalkylene ester[A] is mainly produced; and when the molar ratio is about 4, generallyabout 3.0 to 4.5, the bis(oxyalkylene)ester [B] is mainly produced.

When a polyalkyleneglycol that is not monoetherified is used, themonooxyalkylene ester [A] or bis(oxyalkylene)ester [B] is mainlyproduced as well, depending on the molar ratio used. At the same time, asmall amount of a product [C] of the following formula in which apolyfluoroalkylphosphonic acid is added by condensation to each of theglycol groups at both ends is also produced.C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)(OH)—O(RO)_(m)—P(O)(OH)—(CH₂CH₂)_(c)(CF₂CF₂)_(b)(CF₂CH₂)_(a)C_(n)F_(2n+1)

The separation of each of the unreacted polyalkyleneglycol (monoether),polyfluoroalkylphosphonic acid monooxyalkylene ester, andpolyfluoroalkylphosphonic acid bis(oxyalkylene)ester from the reactionmixture is performed using preparative liquid chromatography; however,the reaction mixture containing the unreacted polyalkyleneglycol(monoether) can be used as it is in the preparation of mold-releasingagents. Since the unreacted polyalkyleneglycol (monoether) has theeffect of reducing the surface tension of water and improvingwettability, there is no need to remove the unreacted polyalkyleneglycol(monoether).

The preparation of a mold-releasing agent using thepolyfluoroalkylphosphonic acid [I] and the polyfluoroalkylphosphonicacid oxyalkylene ester [XI] obtained as above is performed using thepolyfluoroalkylphosphonic acid [I] and the polyfluoroalkylphosphonicacid oxyalkylene ester [XI] at a weight ratio of 1 to 99:99 to 1,preferably 20 to 90:80 to 10 (wherein the weight of [XI] does notinclude the weight of unreacted polyalkyleneglycol or monoetherthereof), and by dilution with water or an organic solvent to form anaqueous solution, aqueous dispersion, or organic solvent solution inwhich the mixture of [I] and [XI] has a solid matters concentration ofabout 0.01 to 30 wt. %, preferably about 0.05 to 3 wt. %.

An example of usable organic solvents is at least one of alcohols, suchas methanol, ethanol, n-propanol, and isopropanol; ketones, such asacetone, methyl ethyl ketone, and methyl isobutyl ketone; ethers, suchas diethyl ether, diisopropyl ether, dioxane, and tetrahydrofuran;esters, such as ethyl acetate and butyl acetate; polyols or ethersthereof, such as ethyleneglycol, propyleneglycol, diethyleneglycol,triethyleneglycol, tetraethyleneglycol, dipropyleneglycol,tripropyleneglycol, tetrapropyleneglycol, diethyleneglycol monomethylether, dipropyleneglycol monomethyl ether, tripropyleneglycol monomethylether, and glycerin; polyvalent alcohol derivatives, such as methylcellosolve, ethyl cellosolve, methyl carbitol, and ethyl carbitol;halogenated hydrocarbons, such as carbon tetrachloride, methylenechloride, trichloroethylene, perchloroethylene, trichloroethane,trichlorofluoromethane, tetrachlorodifluoroethane,trichlorotrifluoroethane, and 1,4-bis(trifluoromethyl)benzene; and thelike. Here, the organic solvent can be used in combination with water.

Other than the above amine neutralizers, the mold-releasing agentsolution may contain, if necessary, various ionic and non-ionicsurfactants for improving the wettability of the mold-releasing agent;silicone oil, silicone varnish, etc., for further improving moldreleasability and lubricity.

The mold-releasing agent solution can be applied to a mold by any commonmethod, such as dipping, spraying, brushing, aerosol spraying, orimpregnated fabric coating. Moreover, examples of molding materials tobe molded with a mold to which the mold-releasing agent is appliedinclude polyurethane, polycarbonate, epoxy resin, phenol resin,polyimide resin, vinyl chloride resin, and other resins; natural rubber,chloroprene rubber, fluororubber, and other rubbers.

EXAMPLES

The following describes the present invention with reference toExamples.

Reference Example 1

(1) In a 1-L, four-necked flask equipped with a thermometer and areceiver for removing low-boiling substances, 500 g (0.92 mol) of acompound of the formula:C₄F₉(CH₂CF₂)(CF₂CF₂)(CH₂CH₂)I (99 GC %)and 213 g (1.84 mol) of triethyl phosphite P(OC₂H₅)₃ were charged, andthe mixture was stirred at 155° C. At this time, to remove theby-product, i.e., ethyl iodide, from the reaction system, nitrogen gaswas bubbled into the reaction solution using a small tube. A slightamount of reaction solution was taken and subjected to gaschromatographic analysis to confirm the remaining amount of triethylphosphite. Thereafter, triethyl phosphite was further added in fourbatches in an amount of 107 g (0.92 mol) per batch, and the mixture wasstirred for 18 hours in total.

After the reaction was completed, the reaction mixture was subjected tosimple distillation under reduced pressure at an internal pressure of0.2 kPa, an internal temperature of 145 to 155° C., and an overheadtemperature of 138 to 142° C. The distillate fraction was washed withwater, thereby obtaining 407 g (yield: 79%) of a purified reactionproduct (98 GC %).

The results of ¹H-NMR and ¹⁹F-NMR confirmed that the resulting purifiedreaction product was a compound represented by the following formula:C₄F₉(CH₂CF₂)(CF₂CF₂)(CH₂CH₂)P(O)OCH₂CH₃)₂

(2) In a 1-L, four-necked flask equipped with a thermometer and acondenser, 300 g (0.53 mol) of the obtained phosphonic acid diester ofthe formula:C₄F₉(CH₂CF₂)(CF₂CF₂)(CH₂CH₂)P(O)(OCH₂CH₃)₂ (96 GC %)and 300 g of about 35% concentrated hydrochloric acid were charged, andthe mixture was stirred at 100° C. for 12 hours. After cooling,filtration under reduced pressure was performed to thereby collect 287 gof solid matters. The solid matters were washed with water and filtratedagain, further followed by acetone washing and filtration, therebyobtaining 240 g (0.49 mol; yield: 93%) of the target product.

The results of ¹H-NMR and ¹⁹F-NMR confirmed that the resulting productwas the target compound (polyfluoroalkylphosphonic acid A; MW: 492, Fcontent: 57.9 wt. %) represented by the following formula:C₄F₉(CH₂CF₂)(CF₂CF₂)(CH₂CH₂)P(O)(OH)₂

(3) In a 500-ml reaction vessel equipped with a stirrer, a nitrogenbubbling device, and a thermometer, 99 g (0.20 mol) of thepolyfluoroalkylphosphonic acid A obtained in Reference Example 1 (2) and201 g (0.40 mol) of polyethyleneglycol monomethyl ether [PEG-a] (UnioxM-550, produced by NOF Corporation; MW=496, m=about 12) of the formula:HO(CH₂CH₂O)_(m)CH₃were charged. After the temperature was raised to 70° C., nitrogenbubbling was performed. Thereafter, the internal temperature of thereaction vessel was raised to 155° C., and 1.2 g of concentratedsulfuric acid was added. The reaction was continued for 48 hours whilethe water produced by the reaction was removed from the reaction systemby continuing nitrogen bubbling in the ongoing reaction.

The obtained reaction mixture was isolated by preparative liquidchromatography, and the composition of the isolated product wasconfirmed by ¹⁹F-NMR and ¹H-NMR. As a result, the weight ratio of PEG-a,product Ia, and product Ib was 50/47/3.

Product Ia (m=about 12):C₄F₉(CH₂CF₂)(CF₂CF₂)(CH₂CH₂)P(O)[O(CH₂CH₂O)_(m)CH₃](OH)Product Ib (m=about 12):C₄F₉(CH₂CF₂)(CF₂CF₂)(CH₂CH₂)P(O)[O(CH₂CH₂O)_(m)CH₃]₂

Reference Example 2

(1) In a 1-L, four-necked flask equipped with a thermometer and areceiver for removing low-boiling substances, 500 g (0.90 mol) of acompound of the formula:C₂F₅(CH₂CF₂)(CF₂CF₂)₂(CH₂CH₂)I (97 GC %)and 208 g (1.80 mol) of triethyl phosphite P(OC₂H₅)₃ were charged, andthe mixture was stirred at 155° C. At this time, to remove theby-product, i.e., ethyl iodide, from the reaction system, nitrogen gaswas bubbled into the reaction solution using a small tube. A slightamount of reaction solution was taken and subjected to gaschromatographic analysis to confirm the remaining amount of triethylphosphite. Thereafter, triethyl phosphite was further added in fourbatches in an amount of 104 g (0.90 mol) per batch, and the mixture wasstirred for 18 hours in total.

After the reaction was completed, the reaction mixture was subjected tosimple distillation under reduced pressure at an internal pressure of0.2 kPa, an internal temperature of 145 to 155° C., and an overheadtemperature of 138 to 141° C. The distillate fraction was washed withwater, thereby obtaining 397 g (yield: 78%) of a purified reactionproduct (97 GC %).

The results of ¹H-NMR and ¹⁹F-NMR confirmed that the resulting purifiedreaction product was a compound represented by the following formula:C₂F₅(CH₂CF₂)(CF₂CF₂)₂(CH₂CH₂)P(O)(OCH₂CH₃)₂

(2) In a 1-L, four-necked flask equipped with a thermometer and acondenser, 300 g (0.52 mol) of the obtained phosphonic acid diester ofthe formula:C₂F₅(CH₂CF₂)(CF₂CF₂)₂(CH₂CH₂)P(O)(OCH₂CH₃)₂ (95 GC %)and 300 g of about 35% concentrated hydrochloric acid were charged, andthe mixture was stirred at 100° C. for 12 hours. After cooling,filtration under reduced pressure was performed to thereby collect 271 gof solid matters. The solid matters were washed with water and filtratedagain, further followed by acetone washing and filtration, therebyobtaining 235 g (0.48 mol; yield: 92%) of the target product.

The results of ¹H-NMR and ¹⁹F-NMR confirmed that the resulting productwas the target compound (polyfluoroalkylphosphonic acid B; MW: 492, Fcontent: 57.9 wt. %) represented by the following formula:C₂F₅(CH₂CF₂)(CF₂CF₂)₂(CH₂CH₂)P(O)(OH)₂

(3) In Reference Example 1 (3), 99 g (0.20 mol) of thepolyfluoroalkylphosphonic acid B obtained in above-mentioned (2) and 201g (0.40 mol) of PEG-a were used, thereby obtaining 276 g (recovery rate:92%) of a light yellow wax-like reaction mixture (F content: 18.8 wt.%).

The obtained reaction mixture was isolated by preparative liquidchromatography, and the composition of the isolated product wasconfirmed by ¹⁹F-NMR and ¹H-NMR. As a result, the weight ratio of PEG-a,product IIa, and product IIb was 50/47/3.

Product IIa (m=about 12):C₂F₅(CH₂CF₂)(CF₂CF₂)₂(CH₂CH₂)P(O)[O(CH₂CH₂O)_(m)CH₃](OH)Product IIb (m=about 12):C₂F₅(CH₂CF₂)(CF₂CF₂)₂(CH₂CH₂)P(O)[O(CH₂CH₂O)_(m)CH₃]₂

Example 1

A mold-releasing agent aqueous solution comprising 0.2 wt. % of thepolyfluoroalkylphosphonic acid A obtained in Reference Example 1 (2),0.3 wt. % of the polyfluoroalkylphosphonic acid oxyalkyleneester-containing reaction mixture (containing unreacted PEG-a) obtainedin Example 1 (3), 99.4 wt. % of ion exchange water, and 0.1 wt. % oftriethylamine was prepared. Using the mold-releasing agent aqueoussolution, mold releasability was evaluated by the following twomeasurement methods. The results were such that the mold releasabilitywas 0.1 N, and the mold release life was 26 times.

<Evaluation of Mold Releasability and Mold Release Life>

Polyurethane prepolymer (100 parts by weight; Coronate C-4090,manufactured by Nippon Polyurethane Industry Co., Ltd.), which had beenheated to 80° C., and 12.8 parts by weight ofmethylene-bis-o-chloroaniline curing agent (Iharacuamine MT,manufactured by Ihara Chemical Industry Co., Ltd.), which had beenheat-melted, were mixed by stirring without forming air bubbles. Themixture was poured into an aluminum mold (diameter: 45 mm, depth: 50 mm)to which the above mold-releasing agent aqueous solution had beenapplied by spraying, and which had been preheated to 80° C. A hook wasstood in the center of the space of the mold for removing the curedmolded product. After heat-curing at 120° C. for 1 hour, the moldedproduct was taken out from the mold by pulling the hook. The moldrelease load required to pull the hook was regarded as moldreleasability. After the mold releasability was thus determined, moldrelease life was determined by measuring how many times a one-timeapplication of the mold-releasing agent aqueous solution allowed moldreleasing at a mold release load of 50 N or less.

Example 2

In Example 1, the amount of polyfluoroalkylphosphonic acid A was changedto 0.4 wt. %, the amount of polyfluoroalkylphosphonic acid oxyalkyleneester-containing reaction mixture was changed to 0.1 wt. %, the amountof ion exchange water was changed to 99.3 wt. %, and the amount oftriethylamine was changed to 0.2 wt. %.

Example 3

In Example 1, the amount of ion exchange water was changed to 85.0 wt.%, and 14.4 wt. % of ethanol was used together with ion exchange water.

Example 4

In Example 1, the same amount (0.2 wt. %) of polyfluoroalkylphosphonicacid B was used in place of the polyfluoroalkylphosphonic acid A.

Comparative Example 1

In Example 1, the polyfluoroalkylphosphonic acid A was not used, theamount of polyfluoroalkylphosphonic acid oxyalkylene ester-containingreaction mixture was changed to 0.5 wt. %, the amount of ion exchangewater was changed to 99.45 wt. %, and the amount of triethylamine waschanged to 0.05 wt. %.

Comparative Example 2

In Example 3, the polyfluoroalkylphosphonic acid A was not used, theamount of polyfluoroalkylphosphonic acid oxyalkylene ester-containingreaction mixture was changed to 0.5 wt. %, the amount of ethanol waschanged to 14.45 wt. %, and the amount of triethylamine was changed to0.05 wt. %.

Comparative Example 3

In Example 1, the polyfluoroalkylphosphonic acid oxyalkyleneester-containing reaction mixture was not used, the amount ofpolyfluoroalkylphosphonic acid A was changed to 0.5 wt. %, the amount ofion exchange water was changed to 99.35 wt. %, and the amount oftriethylamine was changed to 0.15 wt. %.

The following table shows the results obtained in the Examples andComparative Examples above, together with the amount of each componentof the mold-releasing agent aqueous solution (unit: wt. %).

TABLE Example Comp. Ex. 1 2 3 4 1 2 3 [Mold-releasing agent aqueoussolution] Phosphonic acid A 0.2 0.4 0.2 — — — 0.5 Phosphonic acid B — —— 0.2 — — — Phosphonic acid ester- 0.3 0.1 0.3 0.3 0.5 0.5 — containingreaction mixture Ion exchange water 99.4 99.3 85.0 99.4 99.45 85.0 99.35Ethanol — — 14.4 — — 14.45 — Triethylamine 0.1 0.2 0.1 0.1 0.05 0.050.15 [Measurement result] Mold releasability (N) 0.1 0.1 0.1 0.2 4.5 5.014.0 Mold release life 26 24 25 20 10 11 9 (time)

1. A mold-releasing agent comprising as active ingredients, apolyfluoroalkylphosphonic acid represented by the general formula:C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)(OH)₂  [I] whereinn is an integer of 1 to 6, a is an integer of 1 to 4, b is an integer of1 to 3, c is an integer of 1 to 3, or a salt thereof and apolyfluoroalkylphosphonic acid oxyalkylene ester represented by thegeneral formula:C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)[O(RO)_(m)R′]_(d)(OH)_(2−d)  [XI]wherein RO is a linear or branched oxyalkylene group having 2 to 6carbon atoms, R′ is a hydrogen atom, an alkyl group having 1 to 20carbon atoms, or aralkyl group, n is an integer of 1 to 6, a is aninteger of 1 to 4, b is an integer of 1 to 3, c is an integer of 1 to 3,d is an integer of 1 or 2, and m is an integer of 1 to
 100. 2. Themold-release agent according to claim 1, wherein apolyfluoroalkylphosphonic acid monooxyalkylene ester represented by thegeneral formula:C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)[O(RO)_(m)R′](OH)and a polyfluoroalkylphosphonic acid bis(oxyalkylene) ester representedby the formula:C_(n)F_(2n+1)(CH₂CF₂)_(a)(CF₂CF₂)_(b)(CH₂CH₂)_(c)P(O)[O(RO)_(m)R′]₂ areused as a mixture of the polyfluoroalkylphosphonic acid oxyalkyleneester.
 3. The mold-releasing agent according to claim 1, furthercontaining a polyalkyleneglycol or monoether thereof.
 4. Themold-releasing agent according to claim 1, which is used as an aqueoussolution.
 5. The mold-releasing agent according to claim 1, which isused as an aqueous dispersion.
 6. The mold-releasing agent according toclaim 1, which is used as an organic solvent solution.
 7. Themold-releasing agent according to claim 1, wherein thepolyfluoroalkylphosphonic acid oxyalkylene ester thereof have a solidmatters content of 0.01 to 30 wt. %.
 8. The mold-releasing agentaccording to claim 1, which is applied to a molding mold for use.
 9. Themold-releasing agent according to claim 2, further containing apolyalkyleneglycol or monoether thereof.
 10. The mold-releasing agentaccording to claim 2, which is used as an aqueous solution.
 11. Themold-releasing agent according to claim 2, which is used as an aqueousdispersion.
 12. The mold-releasing agent according to claim 2, which isused as an organic solvent solution.
 13. The mold-releasing agentaccording to claim 2, wherein the polyfluoroalkylphosphonic acidoxyalkylene ester thereof have a solid matters content of 0.01 to 30 wt.%.
 14. The mold-releasing agent according to claim 2, which is appliedto a molding mold for use.